A study of low dose peginterferon alpha-2b with ribavirin for the initial treatment of chronic hepatitis C

Antiviral treatment of hepatitis C virus infection and factors affecting efficacy

Hepatitis C virus (HCV) infection is the leading cause of chronic liver-related diseases, including cirrhosis, liver failure, and hepatocellular carcinoma. Currently, no effective vaccine is available for HCV infection. Polyethylene glycol interferon-α (PegIFN-α) in combination with ribavirin (RBV) is the standard of care (SOC) for chronic hepatitis C. However, the efficacy of PegIFN-α and RBV combination therapy is less than 50% for genotype 1 HCV, which is the dominant virus in humans. In addition, IFN and RBV have several severe side effects. Therefore, strategies to improve sustained virological response (SVR) rates have been an important focus for clinical physicians. The serine protease inhibitors telaprevir and boceprevir were approved by the United States Food and Drug Administration in 2011. The addition of HCV protease inhibitors to the SOC has significantly improved the efficacy of treatments for HCV infection. Several direct-acting antiviral drugs currently in late-stage clinical trials, both with and without peg-IFN and RBV, have several advantages over the previous SOC, including higher specificity and efficacy, fewer side effects, and the ability to be administered orally, and might be optimal regimens in the future. Factors affecting the efficacy of anti-HCV treatments based on IFN-α include the HCV genotype, baseline viral load, virological response during treatment, host IL28B gene polymorphisms and hepatic steatosis. However, determining the effect of the above factors on DAA therapy is necessary. In this review, we summarize the development of anti-HCV agents and assess the main factors affecting the efficacy of antiviral treatments.

Very low viral load (VLVL) relapse following treatment of naïve patients with chronic hepatitis C

BACKGROUND

Sustained virologic response (SVR) to treatment of naïve patients with chronic hepatitis C (HCV) with pegylated interferon and ribavirin is 50-60%. Patients who relapse have a poor response to re-treatment. We report a group of relapse patients with SVR to low-dose re-treatment after 6 months.

AIM

Characterization of HCV relapse patients with very low viral load (VLVL) (HCV RNA <5,000 IU/ml) 6 months after stopping full-dose initial treatment.

METHODS

We identified 120 consecutive naïve patients over 4 years treated with pegylated interferon alpha-2a and ribavirin with full-dose therapy for 24 weeks (non-genotype 1) or 48 weeks (genotype 1) with baseline liver biopsy and at least 6 months of follow-up after treatment. HCV RNA by PCR and hepatic blood tests were obtained monthly during treatment and at least 1, 3, and 6 months post treatment.

RESULTS

Of the initially treated patients, 54.2% had SVR, 25% non-response and 20.8% relapsed. Four of 25 who relapsed (16%) and one similar patient referred to our program had HCV RNA <5,000 IU/ml 6 months after stopping treatment (VLVL relapse). Significant differences (P < 0.05) compared with the 21 other relapse patients included all five patients who were genotype 1; 4/5 had cirrhosis, baseline HCV RNA was lower, and all had SVR to less intensive re-treatment for 6 months.

CONCLUSION

VLVL relapse patients should be sought, because SVR to re-treatment is common despite genotype 1 cirrhosis.

Prediction of sustained response to low-dose pegylated interferon alpha-2b plus ribavirin in patients with genotype 1b and high hepatitis C virus level using viral reduction within 2 weeks after therapy initiation

AIM

  Continuation of pegylated interferon (PEG-IFN) plus ribavirin at the recommended dose is difficult in elderly patients and/or patients with cytopenia or complications. Whether the therapeutic efficacy of low-dose PEG-IFN plus ribavirin therapy could be predicted based on virological response within 2 weeks of therapy initiation was evaluated.

METHODS

  A total of 106 patients with a high viral load of genotype-1b hepatitis C virus (HCV) underwent low-dose PEG-IFN plus ribavirin therapy. PEG-IFN alpha 2b (0.75 µg/kg per week) and ribavirin (600-800 mg/day) were administered for 48 weeks.

RESULTS

  Sustained virological response (SVR) was achieved in 37%, and treatment was discontinued in 9%. On univariate analysis of SVR-contributing factors, significant differences were noted in the white blood cell count, platelet count, fibrosis markers, and viral reduction within 2 weeks from therapy initiation. On multivariate analysis, the platelet count and the reduction in the HCV core antigen level at week 2 were independent factors. The positive predictive value (PPV) and the negative predictive value (NPV) for SVR based on a 1-log or greater HCV-RNA level reduction at week 2 were 65% and 90%, respectively, and those based on HCV core antigen level at week 2 were 64% and 97%, respectively. PPV and NPV based on a 2-log or greater reduction of the RNA level were 86% and 67%, respectively, and those based on the core antigen level were 93% and 69%, respectively.

CONCLUSION

  Evaluation of viral reduction at week 2 after therapy initiation is useful for predicting SVR to low-dose PEG-IFN plus ribavirin therapy.

Low- and standard-dose peginterferon alfa-2a for chronic hepatitis C, genotype 2 or 3: efficacy, tolerability, viral kinetics and cytokine response

BACKGROUND

Chronic infection with hepatitis C, genotype 2/3, responds better than other genotypes to peginterferon and ribavirin treatment. We hypothesized that a lower dose of peginterferon would be as effective, but less toxic than standard doses.

AIM

To test the hypothesis that a lower dose of peginterferon would be as effective as, but less toxic than, standard doses.

METHODS

A total of 30 patients were treated with low-dose peginterferon alfa-2a (90 microg/week) and 27 patients with standard doses (180 microg/week) for 24 weeks in combination with 800 mg/day of ribavirin. Patients who failed treatment were offered 48 weeks of standard-dose treatment. Viral and serum inducible protein 10 (IP-10) levels were measured and early viral kinetic parameters were calculated.

RESULTS

Sustained virological response was achieved in 68% of the low-dose and 87% of the standard-dose patients (per protocol, P = 0.79 for non-inferiority). Re-treatment was successful in all patients who tolerated full dose and duration. The standard-dose group had greater first-phase declines of viral levels and faster time to negativity. The second-phase slope was not dose-dependent. IP-10 induction was significantly greater with the standard dose. Although fatigue and general feeling during treatment were worse for standard dose, haematological toxicity and depression did not differ between groups.

CONCLUSION

A lower dose of peginterferon is associated with some symptomatic benefit, but the response is not equivalent to standard dosing.

Prognosis of hepatitis C virus-infected Canadian post-transfusion compensation claimant cohort

Accurate prognostic estimates were required to ensure the sufficiency of the $1.1 billion compensation fund established in 1998 to compensate Canadians who acquired hepatitis C virus (HCV) infection through blood transfusion between 1986 and 1990. This article reports the application of Markov modelling and epidemiological methods to estimate the prognosis of individuals who have claimed compensation. Clinical characteristics of the claimant cohort (n = 5004) were used to define the starting distribution. Annual stage-specific transition probabilities (F0-->F1, . . ., F3-->F4) were derived from the claimants, using the Markov maximum likelihood estimation method. HCV treatment efficacy was derived from the literature and practice patterns were estimated from a national survey. The estimated stage-specific transition probabilities of the cohort between F0-->F1, F1-->F2, F2-->F3 and F3-->F4 were 0.032, 0.137, 0.150 and 0.097 respectively. At 20 years after the index transfusion, approximately 10% of all living claimants (n = 3773) had cirrhosis and 0.5% developed hepatocellular carcinoma (HCC). For nonhaemophilic patients, the predicted 20-year (2030) risk of HCV-related cirrhosis was 23%, and the risk of HCC and liver-related death was 7% and 11% respectively. Haemophilic patients who are younger and are frequently co-infected with human immunodeficiency virus would have higher 20-year risks of cirrhosis (37%), HCC (12%) and liver-related death (19%). Our results indicate that rates of progression to advanced liver disease in post-transfusion cohorts may be lower than previously reported. The Canadian post-transfusion cohort offers new and relevant prognostic information for post-transfusion HCV patients in Canada and is an invaluable resource to study the natural history and resource utilization of HCV-infected individuals in future studies.

Combination therapy of peginterferon and ribavirin for chronic hepatitis C patients with genotype 1b and low-virus load

OBJECTIVE

The aim of this study was to evaluate the efficacy of combination therapy of peginterferon and ribavirin in patients infected with hepatitis C virus (HCV) genotype 1b and low virus load.

METHODS

Inclusion criteria were HCV-genotype 1b, serum HCV RNA level of < 100 KIU/mL at the initiation time of treatment. A total of 60 were enrolled in this retrospective cohort study. The treatment period of combination therapy was 39.8+/-16.1 weeks.

RESULTS

Of the 60 study patients, 47 had sustained virological response (SVR) by the intention to treat analysis. SVR occurred when serum HCV RNA was negative 8 weeks after the initiation of the treatment (p=0.004) and continuance of negative HCV RNA during treatment was > or = 30 week (p=0.016). In rapid virological response, all of seven patients with continuance of negative HCV RNA 20 to 29 weeks during treatment had SVR. In early virological response nine of 10 patients with continuance of negative HCV RNA of 30 to 39 week during treatment had SVR.

CONCLUSION

The duration of combination therapy for chronic hepatitis C should be determined based on the time of attainment of negative HCV RNA in patients with genotype 1b and low-virus load.

Efficacy in patients with dose reduction in combination therapy of peginterferon and ribavirin for chronic hepatitis C

OBJECTIVE

The aim of this study was to elucidate efficacy after dose reduction in combination therapy of peginterferon and ribavirin for chronic hepatitis C.

METHODS

Inclusion criteria were hepatitis C virus (HCV) genotype 1b, serum HCV RNA level of >/=100 KIU/ml, dose reduction of peginterferon and/or ribavirin between the first 4 weeks and 20 weeks after the initiation of treatment. 164 patients were enrolled in this retrospective cohort study. Predictive factors for sustained viral response (SVR) after dose reduction were examined.

RESULTS

Out of the 146 patients treated with dose reduction, 57 had SVR. Multivariate analysis showed that SVR occurred when serum HCV RNA at the time of dose reduction was negative (p < 0.001) and total ribavirin dose was >/=100% of the anticipated total dose (p < 0.001). 57% (55/97) of patients with undetectable serum HCV RNA at the time of dose reduction had SVR. In contrast, only 4% (2/49) of patients with detectable serum HCV RNA at the time of dose reduction had SVR.

CONCLUSIONS

On dose reduction of combination therapy for chronic hepatitis C, undetectable serum HCV RNA at the time of dose reduction and attainment of the total ribavirin dose of >/=100% enhance SVR.

Suitable treatment period in patients with virological response during combination therapy of peginterferon and ribavirin for chronic hepatitis C

OBJECTIVE

The aim of this study was to determine the suitable treatment period in patients who achieve virological response during combination therapy of peginterferon and ribavirin for chronic hepatitis C virus infection.

METHODS

Inclusion criteria were HCV-genotype 1b, serum HCV RNA level of > or =100 KIU/ml before treatment, and negativity of serum HCV RNA during treatment. The 366 patients were enrolled in this retrospective cohort study. Patients were classified into four groups according to difference of response: rapid-virological response (RVR) at week 4 after the initiation of treatment (n=37), early-virological response (EVR) at week 5-12 (n=161), late-virological response (LVR) at week 13-24 (n=131), and superlate-virological response (SLVR) at week 25-48 (n=37). A non-relapse in patients with undetectable HCV RNA during therapy was defined as clearance of HCV RNA 6 month after the cessation of therapy.

RESULTS

Of the 366 patients, 241 had non-relapse and the non-relapse rate in each group was 89% (33/37) in RVR, 79% (127/161) in EVR, 54% (71/131) in LVR, and 27% (10/37) in SLVR. In RVR, 26 of 27 patients with continuance of negative HCV RNA of > or =30 weeks during treatment had non-relapse. In EVR, patients with period of negative HCV RNA of > or =40 weeks had non-relapse rate of 90% (71/79). In LVR and SLVR, all nine patients with continuance of negative HCV RNA of > or =60 weeks had non-relapse.

CONCLUSION

A suitable treatment period of combination therapy for chronic hepatitis C should be determined based on the time of attainment of negative HCV RNA.

Side effects of combination therapy of peginterferon and ribavirin for chronic hepatitis-C

OBJECTIVE

The aim of this study was to elucidate the side effects after combination therapy of peginterferon and ribavirin for Japanese patients with chronic hepatitis C.

METHODS

Inclusion criteria were HCV-genotype 1b and serum HCV RNA level of > 100 KIU/ml. Six hundred and twelve patients were received combination therapy and enrolled in this non-randomized prospective cohort study. Patients were monitored until the discontinuation of combination therapy based on treatment-related side effects. The percentage of each medication actually taken during treatment was calculated.

RESULTS

Sixty-eight patients were stopped the combination therapy due to side effects. The cumulative discontinuation rate due to side effects of therapy was 8.4% at 0.5 year and 14.9% at one year. Discontinuation rate due to side effects was high with statistically significant in the following cases: 1) patients > or = 65 years, 2) patients who had diabetes. Sustained viral response (SVR) was 17.6% (12/68) in the discontinuation group. In the discontinuation group, when the percentage of both peginterferon and ribavirin actually taken during treatment was > or = 60%, SVR was 31% (9/29). On the other hand, when the percentage of each medication actually taken during treatment was < 60%, SVR was 7.7% (3/39). In the discontinuation group, patients with adherence of > 60% to the total of scheduled dose tended to have a high SVR compared to those with < or = 60% adherence to the total of scheduled dose.

CONCLUSION

In combination therapy, patient age and complications of patient are important factors contributing to the safety. In the discontinuation group, patients with adherence of > 60% to the total of scheduled dose tend to have a high SVR.